U.S. Pat. No. 7,713,059 discusses an instrument used for cleaning and/or shaping a channel that exists in or through a solid object. It is designed to shape the channel 3 dimensionally by having the outer contour change as a result of the forces exerted upon it. The downside to this design is that it can only be used with a motor driving the design up and down along the axis of the object. Furthermore, this design does not rotate. For endodontic applications, a majority of the motors available in the dentist office only has rotation ability. This causes the doctor to invest in a new motor. Also, the ability of this design to perform a cut is allowed by changing the surface texture (i.e. roughening the outer surface) to engage and cut into the material (e.g., shaving the root canal at a high speed as it changes shape). Lastly, the method of manufacturing this design is very similar to stents made for the cardiovascular industry where a laser cut of a cylindrical tube is created, which is a very time consuming and costly process. Therefore, the cost of the instrument is much higher than conventional rotary file instruments (approximately 7 times higher).
U.S. Pat. Nos. 6,890,134 and 5,941,760 generally discuss the common process of manufacturing an endodontic rotary file through a grinding procedure. U.S. Pat. No. 6,368,107 shows a design of having a crossing pattern which is similar to the design being shown in the application but the process they have described would not allow the rotary file to change geometry as a result of the forces exerted upon it.